Wastegate Issues

sleepydsm · 10-08-2005

1992 Tsi AWD 5 spd blah blah blah

I have an external HKS standard (40mm) wastgate on my exhaust manifold. It has a "1 bar" spring (its yellow).
Mods:
BR 20G
FMIC
660 Injectors
SAFC(five knob)
GM Maf/Maft
Greddy Type RS BOV
255 Fuel Pump
Adjustable FPR
CAI

My Setup:
I put a manual boost controller on my car today, preping for the RF rice day tomorrow. I put the MBC on a line going directly to my wastgate. That vaccum line starts at the intake manifold, goes to a t, and then to the wastegate. My bov is hooked off the T fitting.

The Problem:
At WOT, maybe 85%+ throttle at least, when the boost goes past 20 the car studders and shakes. Its as if the wastgate is fluttering, kinda like howa a BOV does. This only happens when there is a boost controller on the car, and its above 20 PSI. Anyone have any ideas whats wrong? I assume my wastegate is fine because it works as it should when the MBC is NOT hooked up. Thanks!

Kevin

Swifty1638 · 10-08-2005

you sure it's not misfiring? pulling timing? Cause it's bad to run higher then 18 psi on pump..you running around on bonnie and steve's 111?

-A. Swift

dsm10sec · 10-08-2005

Quote:

Originally Posted by Swifty1638

Cause it's bad to run higher then 18 psi on pump..

MAYBE if you dont have control of timing...

Swifty1638 · 10-08-2005

true, but the fuel characteristics of 93 octane these days..I'd never run higher then 18 psi on pump..would you? timing only gets you so far..

-A. Swift

TheBlizzard · 10-08-2005

Saying you can't run that much boost on pump is a very general statement. All cars are different and just because your doesn't like it doesn't mean the next car will not. It has a lot to do with what turbo he has as well as his supporting mods, if he has a 14b I would be more worried about all the hot air coming out of that turbo at 20lbs than I would be about timing or anything else.

Sleepy, you are going to have to list more about your car in this case because if you don't have sufficient supporting mods then yes you could be just running to much boost which could be causing a lot of problems. Edit your first post with more information or I will delete this thread all together because the only answers your going to get from your question are assumptions.

CDeutsch · 10-08-2005

If it feels like the BOV then maybe it is.

You could try giving it it's own Vac/Boost source. What BOV is it and is it vented to atmosphere? Need more info, like TheBlizzard said.

blageo23 · 10-09-2005

I could maybe list the mods hes got. So when he checks it he might have the answer.
His Mods:
BR 20G
FMIC
660 Injectors
SAFC(five knob)
GM Maf/Maft
Greddy Type RS BOV
255 Fuel Pump
Adjustable FPR
CAI
That should be All the info you should need.

**JET** · 10-09-2005

20 psi might be it on pump gas with that setup. With some tuning you might be able to run a tad more. Try retarding the base timing 3* or so and see how much that helps.

sleepydsm · 10-09-2005

Thanks Mike for listing that info. Sorry for not listing enough info! And yes I'm pretty sure it's just my retarded Greddy Type RS. I think it just isnt set hard enough to hold that kind of boost. And I'm not ghey enough to use 93 octane, I use BP 92

And maybe one day I'll get me a 5 gallon pail of VP import for the hell of it.

TheBlizzard · 10-09-2005

BP 92 is better than Holiday 93 or most other pump gases so you are using the right fuel. And if you blow off valve wasn't holding the boost it would just leak out, I doubt it would studder and shake like that unless it was somehow surging.

Like I said earlier it all depends on your car, some cars like more boost with less timing and some cars like less boost with more timing. In most casing more boost equals more power even with less timing. So in my opinion you would be better off lowering your base timing and then try to run more boost and see if it doesn't knock.

And as far as your BOV goes, if you adjust it and it doesn't go away then try a different one to rule that out. There is a chance that the WG might be messed up to but the symptoms from that are going to vary depending on whats wrong with it. I think Shanes WG messed up recently, maybe he can shed some light on what happens when they take a shit on you.

CDeutsch · 10-09-2005

If possible, recirculate your BOV and see if it goes away. I'd start there to rule it out.

Could be spark blowout if it's happening at WOT, I've only had problems with BOVs at part throttle (so far).

sleepydsm · 10-09-2005

Ok, well I tightened the BOV. That problem is solved. BUT with a boost controller on, the boost flies up to whatever it wants. It acts as if the wastegate is not hooked up.
This is hard to explain, sorry. The car only jerks and studders when you're at partial throttle, and the boost is building up. It gets to a certain point and just bucks and jerks around. At WOT, the car is fine, its just the boost is uncontrolled so that is a problem. Without a boost controller, my wastegate works fine. When the MBC is hooked up, the wastegate acts like it isnt seeing boost/vaccum. (so basically the boost is uncontrolled, and goes to whatever). I originally had an Elite MBC, so I tried another one. And the same problem is happening. And yes the screw is back out as far as possible. Any ideas? I'm gonna do a boost leak test, and see if possibly the MBC is leaking somehow, and therefore the wastgate acts as if it is NOT hooked up.

On another note, I wasn't having an issue with knock at all. I was hoping to run about 18-20 psi on 92 pump gas.

Thank you all for your input!
Kevin Swalchick.

**Shane@DBPerformance** · 10-09-2005

Are you hooking the boost controllers up backwards?

sleepydsm · 10-09-2005

They were not hooked up backwards. I put an Elite MBC back on, and it actually controls the boost. The other shitty one I had... the spring was WAY too stiff.

Ok, now on another note. The BOV is set a lot stiffer, I have a MBC that controls boost, and its set at about 20psi in 3rd. In 2nd gear at about 5-6K RPM I get a loud pop the car jerks. Again, it feels like the wastegate is opening. Could it be the BOV again? (too stiff, not stiff enough). Some sort of ignition problem? Or just some kind of tuning issue (way too rich)?

Again, thanks for all the help. Thats why this board is awesome.

**JET** · 10-09-2005

Alright, set the boost to 15 lbs and tune the car there. That will get you a rough tune, then bump it up from there. Don't try and go straight to 20 lbs, it is way too difficult to tune it close to the ragged edge, especially with nowhere to start and a novice tuner. I don't even think you should run around at 20 psi until you have it totally dialed in at 17 or so.

**Shane@DBPerformance** · 10-09-2005

Quote:

Originally Posted by sleepydsm

In 2nd gear at about 5-6K RPM I get a loud pop the car jerks.

Fuel cut? If it's a hard jerk, it might be fuel cut. If it's just a sputtering then it could be an ignition problem or just way too rich.

dsm10sec · 10-09-2005

Look on your MAFT and find out if the dipswitch on it is set to fuel cut on or off.

sleepydsm · 10-10-2005

OK. Thank you all for the advice. I will do what JET suggested, I'm gonna turn down the boost and work from there. I'm pretty sure its a tuning issue. At about 4500 rpm, I would get 20 counts of knock, no matter how much more fuel I'd add. As soon as it hits about 4500rpm, in any gear above 1st, as long as I'm making boost, it jerks and knocks.

BUT... I did get a check engine light, it said Code 44. Ignition coil... This problem has been around for a bit, I replaced the ignition transistor pack thing (not the coil) and it seemed to go away. Could a faulty coil be one of the causes for this problem?

Could an ECU on the way to Shitsville cause any of this either... I've never replaced the caps...

slowbubblecar · 10-10-2005

The coil can cause a misfire because a cylinder or 2 might not be getting spark. I think the wastegate has a 20 pound spring in it. I had the car run good at 20psi and pump gas before with that turbo. The 60 trim worked well at 25 pump with no knock.

sleepydsm · 10-10-2005

The spring in the wastegate is yellow. Looking in my handy HKS catolog, the yellow spring for a standard wastegate is 14.7psi, or 1 BAR, as it says on the wastegate written with a Sharpie

Well then I'm gonna get an OEM coil, and see whats going on then.

No matter what I get a misfire/popping/jerking motion at 4500rpm. About 20 counts of knock no matter how much fuel I add.

I'll get a coil soon. Until then I'll try and take 'er easy. Driving like a grandma sucks.